<template>
    <div class="type-nav">
            <div class="container">
                <div  @mouseleave="leaveShow" @mouseenter="enterShow">
                    <h2 class="all">全部商品分类</h2>
                    <!-- 过渡动画 -->
                    <!-- <transition name="sort"> -->
                        <!-- 三级联动 -->
                        <div class="sort" v-show="show">
                            <div class="all-sort-list2"  @click="goSearch">
                                <div class="item" v-for="(c1,index) in categoryList.slice(0,15)" :key= "c1.categoryId" :class="{shiroha:currentIndex==index}">
                                    <h3 @mouseenter="changeIndex(index)">
                                        <a :data-categoryName="c1.categoryName" :data-category1Id="c1.categoryId">{{c1.categoryName}}</a>
                                    </h3>
                                    <!-- 二级与三级分类 -->
                                    <div class="item-list clearfix" :style="{display:currentIndex==index?'block':'none'}">
                                        <div class="subitem" v-for = "c2 in c1.categoryChild.slice(0,10)" :key="c2.categoryId">
                                            <dl class="fore">
                                                <dt>
                                                    <a :data-categoryName="c2.categoryName" :data-category2Id="c2.categoryId">{{c2.categoryName}}</a>
                                                </dt>
                                                <dd>
                                                    <em v-for="c3 in c2.categoryChild" :key="c3.categoryId">
                                                        <a :data-categoryName="c3.categoryName" :data-category3Id="c3.categoryId">{{ c3.categoryName }}</a>
                                                    </em>
                                                </dd>
                                            </dl>
                                        </div>
                                    </div>
                                </div>
                            </div>
                        </div>
                    <!-- </transition> -->
                </div>
                <nav class="nav">
                    <a href="###">服装城</a>
                    <a href="###">美妆馆</a>
                    <a href="###">超市</a>
                    <a href="###">全球购</a>
                    <a href="###">闪购</a>
                    <a href="###">团购</a>
                    <a href="###">有趣</a>
                    <a href="###">秒杀</a>
                </nav>
               
            </div>
        </div>
</template>

<script>
import {mapState} from 'vuex'
import throttle from 'lodash/throttle'

    export default{
        name:'TypeNav',
        data(){
            return{
                //存储用户鼠标移到哪个一级分类上
                currentIndex:-1,
                show:true
            }
        },
        // 组件挂载完毕时向服务器发送请求
        mounted(){
            if(this.$route.path!='/home'){
                this.show = false
            }
        },
        computed:{
            ...mapState({
                // 注入一个参数state，该state为大仓库中的数据
                categoryList:state=>state.home.categoryList
            })
        },
        methods:{
            // 鼠标事件,碰到变色
            // 对函数进行截流操作
            changeIndex: throttle(function(index) {
                 // index:鼠标移上某一个一级分类的元素的索引值
                 this.currentIndex = index
            },50),
            leaveIndex(){
                this.currentIndex = -1
            },
            goSearch(event){
                this.$router.push('/search')
                let element = event.target
                // 获取到当前触发这个事件的节点，该节点一定为带有data-categoryname属性的a标签
                // dataset,可以获取节点的自定义属性与属性值
                let {categoryname,category1id,category2id,category3id} = element.dataset
                if(categoryname){
                    // 整理路由跳转参数
                    let location = {name:'search'}
                    let query = {categoryName:categoryname}
                    if(category1id){
                       query.category1Id = category1id
                    }else if(category2id){
                       query.category2Id = category2id
                    }else{
                        query.category3Id = category3id
                    }
                    // 判断是否有params参数，有则合并参数
                    if(this.$route.params){
                        location.params = this.$route.params
                        // 整理完参数
                        location.query = query
                        // 路由跳转
                        this.$router.push(location)
                    }
                    
                }
            },
            // 当鼠标移入的时候，让商品分类列表进行展示
            enterShow(){
                if(this.$route.path !='/home'){
                    this.show = true
                }
            },
            // 当鼠标离开的时候，让商品分类进行隐藏
            leaveShow(){
                this.currentIndex = -1;
                // 只有是search路由组件时才执行
                if(this.$route.path !='/home'){
                    this.show = false
                }
            },
        },
    }
</script>

<style  lang="less" scoped>
    a{
        text-decoration: none;
    }
    .type-nav {
        border-bottom: 2px solid #e1251b;

        .container {
            width: 1200px;
            margin: 0 auto;
            display: flex;
            position: relative;

            .all {
                width: 210px;
                height: 45px;
                background-color: #e1251b;
                line-height: 45px;
                text-align: center;
                color: #fff;
                font-size: 14px;
                font-weight: bold;
            }

            .nav {
                a {
                    height: 45px;
                    // text-decoration: none;
                    margin: 0 22px;
                    line-height: 45px;
                    font-size: 16px;
                    color: #333;
                }
            }

            .sort {
                position: absolute;
                left: 0;
                top: 45px;
                width: 210px;
                height: 461px;
                position: absolute;
                background: #fafafa;
                z-index: 999;

                .all-sort-list2 {
                    .item {
                        h3 {
                            line-height: 30px;
                            font-size: 14px;
                            font-weight: 400;
                            overflow: hidden;
                            padding: 0 20px;
                            margin: 0;

                            a {
                                // text-decoration: none;
                                color: #333;
                            }
                        }

                        .item-list {
                            display: none;
                            position: absolute;
                            width: 734px;
                            min-height: 460px;
                            background: #f7f7f7;
                            left: 210px;
                            border: 1px solid #ddd;
                            top: 0;
                            z-index: 9999 !important;

                            .subitem {
                                float: left;
                                width: 650px;
                                padding: 0 4px 0 8px;

                                dl {
                                    border-top: 1px solid #eee;
                                    padding: 6px 0;
                                    overflow: hidden;
                                    zoom: 1;

                                    &.fore {
                                        border-top: 0;
                                    }

                                    dt {
                                        float: left;
                                        width: 54px;
                                        line-height: 22px;
                                        text-align: right;
                                        padding: 3px 6px 0 0;
                                        font-weight: 700;
                                    }

                                    dd {
                                        float: left;
                                        width: 415px;
                                        padding: 3px 0 0;
                                        overflow: hidden;

                                        em {
                                            float: left;
                                            height: 14px;
                                            line-height: 14px;
                                            padding: 0 8px;
                                            margin-top: 5px;
                                            border-left: 1px solid #ccc;
                                        }
                                    }
                                }
                            }
                        }

                        // &:hover {
                        //     .item-list {
                        //         display: block;
                        //     }
                        // }

                    }
                    .shiroha{
                        background: skyblue;
                    }
                }
            }

            // // 过渡动画的样式
            // // 开始状态
            // .sort-leave{
            //     height: 461px;
            // }
            // // 过渡动画结束状态(进入)
            // .sort-leave-to{
            //     height: 0px;
            // }
            // //定义动画时间，速率
            // .sort-leave-active{
            //     transition: all .3s linear;
            // }

        }
    }
</style>